After the Broken Engagement, I Use Science to Strengthen the Nation, and the Stern Commander Regrets It

[Alternate history + period setting + academic ace + top research scientist + face-slapping + real and fake heiresses + strengthening the nation through science and technology] After winning an award, a mechanical genius from the 21st century opens her eyes and finds herself in 1977, in the body of a pitiful girl with the same name. The poor girl was schemed against and had her engagement broken off. Her scumbag father even wants her to give her university spot to his stepdaughter. Sheng Anning: Want it? Pay up! Later… Her mentor shows up with her husband, and she discovers that she's actually the biological daughter her mentor accidentally switched at birth in her previous life, the one who died young! She teams up with her birth mother to do research, living and eating at the research institute. Her birth father gets angry: Hurry up and get married! Give your mother back to me! Sheng Anning: I'm still recovering from the trauma of my last broken engagement! Shi Jingyao returns to the capital: You spread rumors about me? Who said I broke off our engagement? Later still… A domineering, sharp-tongued young woman appears at Qingbei. No one wants to talk to her. The others compete over whose father or mother has the most clout. Sheng Anning turns in rice transplanters and harvesters, and radically upgrades fishing boats. The whole nation has enough to eat! The others burn the midnight oil studying. Sheng Anning whips up a 1.8nm process lithography machine. Research institutes all over the country extend invitations… She gives a casual wave: Thanks, but no thanks! I've already joined the “national team.” Neighboring small countries start causing trouble. She modifies planes, cannons, and a giant aircraft carrier, scaring them into sending friendly negotiation terms overnight… A certain alliance threatens Great Hua, demanding that they hand her over. Seated at the head of the state banquet table, she sketches out several kinds of guided missiles. “Tell them, if they don't like it, bring it on.” Great Hua is hit with economic sanctions… Sheng Anning is well and truly furious. Internet, attack dogs! A certain video app goes global. People around the world are captivated. It can do that? But Sheng Anning isn't done yet! You've learned Great Hua's culture? That's cultural invasion! You're using Great Hua's high-tech products? That's economic robbery! The people: “No regrets in this life for being born in Great Hua. In the next life, we'll still be citizens of the Flowering Land.”